A year of official mourning for Thailand's late King Bhumibol Adulyadej was to end Sunday after a lavish five-day funeral full of pageantry and religious ritual.

Bhumibol, a beloved monarch who died last October aged 88, was cremated on Thursday after a day charged with emotion that brought the nation to a standstill.

At his death he was the world's longest-serving monarch, spanning seven decades of Thailand's turbulent modern history to become its leading symbol of unity.

But he left behind a kingdom deeply divided along political, economic and social lines, with a military junta in charge and democratic government a distant prospect.

As dusk fell on Sunday, Bhumibol's son and heir 65-year-old King Maha Vajiralongkorn and his sister, Princess Maha Chakri Sirindhorn, carried a pair of golden urns containing their father's relics from the Grand Palace to two Bangkok temples where they will be housed.

A ceremonial cavalry unit with soldiers in full regalia -- including blue plumes in their helmets -- led the convoy, in a sombre but small procession capping the $90 million funeral.

Buddhist monks led prayers at the temples while black-clad mourners sitting on pavements outside clasped their hands together in respect.

Bhumibol's reputation as "father of the nation" was burnished by a careful palace PR machine, while criticism of the king and key senior royals is banned under a tough lese majeste law.

Thais have dressed in black or subdued tones for much of the last year, with black and white ribbons tied to school gates, temples and government buildings.

The prolonged display of official mourning for the late king ends at midnight on Sunday.